In my previous U.S. Pat. No. 3,724,862 which issued Apr. 3, 1973, there is disclosed a rotating blow-out preventor, hereinafter called "RBOP", having associated therewith a seal means for preventing contamination of various moving parts thereof. Reference is made to this issued patent for further background of the invention.
In my co-pending patent application, Ser. No. 339,037 filed Mar. 8, 1973, now U.S. Pat. No. 3,868,832, granted Mar. 4, 1975 there is disclosed improvements in RBOP, which enable rapid replacement of a stripper rubber which receives a tool string therethrough. Reference is made to this patent application as well as the art cited therein for further background of the invention.
In making hole with a rotary drilling rig, sometime formations are encountered such that several days will expire between trips for replacement of the drill bit. Such an occurrence is always favorably received by the Roughnecks for the reason that they can lounge about the rig or recline in the doghouse, since the only work that must be accomplished is an occasional addition of another joint of drill pipe to the Kelly. In making a deep hole, should the RBOP become unduly worn, a dangerous situation exists because a pocket of gas might be encountered and control of the well will thereby be lost. This is, of course, a catastrophic occurrence in the oil patch.
Therefore, it is desirable to have an RBOP designed in such a manner to enable the stripper, as well as the bearings and various seals associated therewith, to be replaced without the necessity of removing the massive main housing of the RBOP from the upper extremity of the surface casing.